Activated abilities contain a colon. They’re generally written “[Cost]: [Effect].” Some keywords are activated abilities and will have colons in their reminder text.

Squelch can’t target a mana ability because mana abilities don’t use the stack.

Squelch : règles, fonctionnement et interactions (MTG)

Squelch is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Counter target activated ability. (Mana abilities can't be targeted.) Draw a card.

How it works : Squelch

Original English text — Wizards of the Coast / Scryfall

#1June 8, 2016· Wizards of the Coast
Activated abilities contain a colon. They’re generally written “[Cost]: [Effect].” Some keywords are activated abilities and will have colons in their reminder text.
No other card is named in this ruling.
#2December 1, 2004· Wizards of the Coast
Squelch can’t target a mana ability because mana abilities don’t use the stack.
No other card is named in this ruling.